The invention relate to printwheel setting apparatus and more particularly to printwheel setting mechanisms for postage meters.
Printwheel setting mechanisms are well known and are described for example in U.S. Pat. No. 4,579,054 issued to Buan, et al. in respect to printwheels for value printing in a flat-bed printer. In addition to the value printing, postage meters typically are required to print a date, and normally allow selection of a slogan for printing on a mailpiece. Some postage metering devices serve as parcel register to provide shipping information for parcel carrier services. These register are typically required to print a parcel identification number (PIN) for each parcel. The number is normally increased in sequence for successive parcels.
Typically, in conventional postage meters the selection of the date and slogan will be done manually. The indexing of the partial identification number then is normally done automatically. Thus, each of the various printing elements are separately mounted and separately actuated by the operator or from the register.
U.S. Pat. No. 4,398,458 discloses a date-setting mechanism for automatically setting a date in response to a keyboard actuation. U.S. Pat. No. 4,649,489 also discusses an aspect of date-setting through the keyboard. U.S. Pat. No. 4,321,867 discloses a PIN number setting device for a drum-type postage meter.
U.S. Pat. No. 3,832,946 to Lupkas discloses a value printing mechanism using a solenoid actuated drive for setting and encoding printwheels.
Conventionally, the dater printwheels of postage meters are set manually. Each has a detent to provide accurate positioning as well as a degree of "float" to help to keep all printwheel members in a common plane. It was found that the torque necessary to overcome the detent makes high speed automatic setting of the printwheels difficult.
It is an object of the invention to provide a setting mechanism for printwheels in which the printwheel detent is in place when the wheel is stationary for providing alignment and "float" and in which the detent is deactivated when it is desired to turn the printwheel.